A53.9 – Syphilis, unspecified

ICD-10-CM 2027 diagnosis code · Infections with a predominantly sexual mode of transmission

Billable code

ICD-10-CM code A53.9

Code: A53.9 (claims format: A539)
Description: Syphilis, unspecified
Billable: Yes – valid for HIPAA-covered transactions
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 1. Certain infectious and parasitic diseases (A00-B99)
Block: A50-A64 Infections with a predominantly sexual mode of transmission
Parent codes: A53

Notes for A53.9

Applicable to:

Infection due to Treponema pallidum NOS
Syphilis (acquired) NOS

Excludes1 (not coded here):

syphilis NOS under two years of age (A50.2)

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Block A50-A64

Excludes1 (not coded here):

nonspecific and nongonococcal urethritis (N34.1)
Reiter's disease (M02.3-)

Excludes2 (not included here):

human immunodeficiency virus [HIV] disease (B20)

Index terms for A53.9

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in A53

A53.0 – Latent syphilis, unspecified as early or lateBillable

Frequently asked questions

What is ICD-10 code A53.9?

A53.9 is the ICD-10-CM code for syphilis, unspecified, in the block A50-A64 (Infections with a predominantly sexual mode of transmission).

Is A53.9 a billable code?

Yes. A53.9 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does A53.9 belong to?

It belongs to category A53 – Other and unspecified syphilis.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.